Strengths and Limitations of the Two Approaches

Ammonia cracking for hydrogen production essentially serves as a hydrogen storage, transport, and release technology, with ammonia functioning solely as a hydrogen carrier. It addresses the challenges of long-distance green hydrogen transportation, seasonal and regional supply-demand mismatches, enabling hydrogen to be produced and consumed locally at the point of use. However, the preceding step involves synthesising green ammonia. This entails using green hydrogen produced via water electrolysis (as mentioned earlier) to synthesise green ammonia with nitrogen gas under high-temperature, high-pressure conditions using the Haber-Bosch process. This green ammonia is then stored, transported to the point of use, and reconverted into hydrogen through ammonia cracking before its application.This step appears counterintuitive to many, as multiple energy conversions within the chain inevitably incur losses, seemingly substantially increasing hydrogen's utilisation costs. However, hydrogen storage networks remain highly immature. Compared to constructing hydrogen storage and transport infrastructure, liquid ammonia storage and transport benefit from a century of industrial foundation, enabling direct utilisation for transnational and intercontinental storage and transport.

From these two descriptions, it becomes clear what problems electrolytic hydrogen production and ammonia cracking respectively address. Electrolytic hydrogen production can absorb renewable energy, enable industrial-scale continuous hydrogen production, and reduce the levelised cost of hydrogen (LCOH). Ammonia cracking, meanwhile, facilitates the long-distance transport of green hydrogen, resolves seasonal and regional supply-demand mismatches, and enables hydrogen to be produced and consumed locally at the point of use. Thus, ammonia cracking is not merely "another hydrogen production method," but the "key" to scaling hydrogen energy applications. Without ammonia cracking, numerous electrolysis projects would remain stranded.

Globally, the cheapest green electricity currently resides in South America, Australia, the Middle East, and North Africa, while the greatest hydrogen demand lies in industrial clusters across East Asia and Europe. Without ammonia as an intermediate form, numerous large-scale water electrolysis projects would prove economically unviable, trapping green hydrogen within isolated production hubs. In practical terms, ammonia cracking offers viable alternatives to water electrolysis in scenarios such as high-pressure hydrogen cylinder trailers, liquid hydrogen transport, and prohibitively costly long-distance pipelines.

Herein lies the clarity: ammonia cracking and water electrolysis are not in competition; they occupy distinct positions within the hydrogen value chain. More accurately, ammonia cracking does not diminish the value of electrolysis but rather "expands the accessible market for electrolysis".